Earlier Established Forms

Sources

found: On an expansion apparatus for making visible ..., 1912?:t.p. (C.T.R. Wilson)

found: Wikipedia, viewed August 21, 2015(Charles Thomson Rees Wilson, CH, FRS (14 February 1869 - 15 November 1959) was a Scottish physicist and meteorologist who received the Nobel Prize in physics for his invention of the cloud chamber.) {https://en.wikipedia.org/wiki/Charles_Thomson_Rees_Wilson}